Effects of active immunization against somatostatin or somatostatin analogues on milk production in rats.

摘要

Effects of active immunization against various forms of somatostatin on milk production were investigated in rats. Somatostatin-14, somatostatin-28, or three different somatostatin analogues were conjugated to bovine serum albumin for immunogen preparation. 70 female Sprague-Dawley rats were divided into 7 groups and immunized against phosphate buffer (control 1), bovine serum albumin (control 2), somatostatin-14, somatostatin-28, or one of the somatostatin analogues (Octreotide, Tyr3-octreotide, and MK 608) at 5 weeks of age. Booster immunizations were performed at 7, 9, 12 weeks of age. Only somatostatin-14 injection induced the production of anti-somatostatin antibodies. There were no differences in blood somatotropin and insulin-like growth factor concentrations and growth performance between somatostatin-14 group (with anti-somatostatin antibodies) and other groups (without the antibodies). In addition, mammary DNA, RNA, and protein contents, and the ratio of RNA to DNA and protein to DNA ofsomatostatin-14 group were not different from those of the other groups. Although rats immunized against somatostatin-14 showed the highest milk production among all groups, there was no statistical significance.